CN1650050A - Electrode constructs, and related cells and methods - Google Patents

Abstract

Described are preferred articles of manufacture useful as electrode structures which desirably include multiple thin conductive layers stably bonded to an electrode substrate through a bonding layer. Also described are preferred articles of manufacture useful as electrode structures which include reinforcing carbon layers, which include an embrittlement-sensitive material and a protective oxygen-free copper layer, and which include at least one thin metal layer including a bamboo grain pattern. Additional embodiments of the invention include electric or other reaction cells incorporating such electrode structures, and methods for their operation.

Description

Electrode Construction, Related Cells and Methods

Background technique

The present invention relates generally to batteries, and in one particular aspect to batteries having a cathode incorporating multiple thin film metal layers.

As further background, electrolyte cells of various designs incorporating multilayer thin films have been proposed. For example, Miley et al. used flat stainless steel plates coated with multilayer thin films as electrodes for electrolyte cells. These experiments are described in "Electrolytic cell with Multilayer Thin-Film Electrode" published by G.Miley, H.Hora, E.Batyrbekov, and R.Zich, Trans.Fusion Tech., Vol. 26, No. 4T, Part 2, pp. 313-330 (1994). In this prior work, alternating thin film (100-1000 Angstrom) layers of two different materials (eg titanium/palladium) were employed. Others have proposed using packed-bed electrolyte cells, in which small plastic pellets are coated with layers of different materials a few micrometers thick. See, eg, U.S. Patent Nos. 4,943,355; 5,036,031; 5,318,675 and 5,372,688.

Other electrolyte cells employ various forms of coated electrodes. For example, U.S. Patent No. 4,414,064 entitled "Method For Preparing Low Voltage Hydrogen Cathodes" discusses a first metal (such as nickel), a leachable second metal, or a metal oxide ( such as tungsten) and a non-leachable tertiary metal such as bismuth.

In light of these previous efforts, there remains a need for other improved and/or alternative cell designs incorporating thin film (eg, 10-10,000 Angstrom thick layers) electrode configurations. The present invention meets this need.

Contents of the invention

In one aspect, the invention provides an article useful as an electrode configuration, such as may be used in batteries. An electrode construction or other similar article includes a non-conductive substrate, and a metal adhesive coating bonded to the non-conductive substrate. At least one layer of a first conductive metal is bonded to the metal adhesion coating. At least one layer of second conductive metal is bonded to the first layer of conductive metal. The metal layer of the construction is preferably very thin, for example having a thickness of less than about 10,000 Angstroms, typically about 10 to about 10,000 Angstroms. Desirably, the electrode configuration comprises multiple layers of the two metals, or alternating layers of the two metals combined with one or more other metals in a repeating sequence. In addition, preferred adhesive coatings for bonding to silicon-containing substrates include multiple layers, such as having a tantalum nitride layer bonded to the substrate, and a tantalum layer bonded to the tantalum nitride layer (which α-tantalum), and copper or another metal bonded to the tantalum layer.

In another embodiment, the invention relates to an article comprising a substrate and a material on the substrate that is susceptible to embrittlement, for example by the introduction of ions of hydrogen or an isotope thereof (eg deuterium). A protective layer is provided over the embrittlement-sensitive material and includes oxygen-free copper. In a preferred embodiment, the embrittlement-sensitive material is tungsten or a tungsten compound, such as tungsten nitride. Preferred articles include, for example, electrode structures useful in the construction of batteries.

Another preferred embodiment of the present invention provides articles such as electrodes useful in batteries. The electrode or other similar article includes a plurality of thin metal layers and an amorphous carbon layer adjacent to the thin metal layers. For example, an amorphous carbon layer may be used to encase a thin metal layer to act as a protective barrier, and/or may simply be in heat transfer relationship with and to dissipate heat from the thin metal layer.

In another aspect, the invention provides articles, such as electrodes useful in batteries, including electrodes or similar structures having multiple thin metal layers. The plurality of thin metal layers includes a repeating sequence of at least three different metal layers.

Another aspect of the invention provides an electrode or similar article useful in a battery, comprising an electrode structure having a plurality of thin metal layers. At least one metal layer, and preferably multiple layers thereof, comprises a lanthanide metal.

In a still further embodiment of the present invention there is provided a battery-useful article, such as an electrode, having a plurality of thin metal layers, wherein at least one of the thin metal layers has a pattern of bamboo grains.

In a further embodiment, the present invention provides a method for localizing the concentration of ions of hydrogen or isotopes thereof, comprising providing an article as described above, and causing localized concentrations of these ions in the article.

The invention also includes batteries incorporating the electrode configurations described herein, and to methods of operating these batteries.

The present invention provides improved and alternative electrode and battery designs and uses thereof. Other embodiments of the invention, as well as features and advantages, will be apparent from the description herein.

Description of drawings

Figure 1 provides a schematic illustration of a cross-section of a preferred electrode device of the present invention.

Figure 2 shows the relative solubility of hydrogen in various metals.

Figure 3 shows the relative permeability of hydrogen in various metals.

preferred embodiment

In order to facilitate an understanding of the principles of the invention, reference will now be made to certain preferred embodiments thereof and specific language will be used to describe it. It should be understood, however, that the scope of the present invention is not limited thereto, and that changes, further modifications and applications of the principles of the present invention described herein are generally within the reach of those skilled in the art to which the present invention pertains.

As disclosed above, the present invention provides electrode constructions and related conductive articles, batteries incorporating these electrode constructions, and methods of operating electrode batteries.

Referring now to Figure 1, a preferred electrode arrangement of the present invention is shown. The electrode device 10 comprises a substrate 11 made of a suitable material. The substrate 11 is preferably non-conductive, for example composed of a non-conductive material such as a cross-linked polymer, ceramic, or glass. The electrode substrate 11 is preferably made of silicon-containing material. Other suitable substrate materials may also be used within the scope of the present invention, as will be understood by the skilled artisan.

The electrode device 10 includes an adhesive coating 12 that may be formed from a single layer of material or multiple layers of material (eg, as shown at 12a-12d). The adhesive coating 12 is used to more stably finally bond the working electrode structure 13 to the electrode substrate 11 . Working electrode 13 may consist of a single thin-film metal layer, but preferably includes multiple thin-film layers including at least one conductive (metal) layer and optionally one or more non-conductive layers. Illustratively, working electrode 13 may include layers 13a-13c as shown in FIG. It is understood in this regard that the working electrode 13 may comprise even more thin film layers. In many applications of the invention, the working electrode is expected to comprise from about 2 to about 50 thin film layers. The preferred electrode device 10 also includes barrier layers 14a-14c covering the top and sides of the electrode device. In some embodiments, device 10 also includes a thermoelectric element 15 in heat transfer relationship with the electrode structure.

Various aspects of the inventive electrode device and its manufacture are now discussed in more detail.

As disclosed above, in one aspect, the present invention provides an electrode device comprising a copper layer on top of a tantalum nitride/α-tantalum combination adhered to a substrate. In these preferred embodiments, the electrode comprises a silicon-containing substrate (11), a silicon dioxide layer (12a), a tantalum nitride layer (12b), an alpha-tantalum layer (12c), a copper layer (12d), and a working electrode 13 and barrier layer 14. In other aspects of the invention, metals other than copper are bonded to the underlying structure. Preferred materials for these purposes are metals that can be deposited as thin films, and have a melting point greater than 150 degrees Celsius. Also, the substitution for copper in this combination preferably minimizes the lattice structure between species with respect to the underlying tantalum layer (ideally α-tantalum) (e.g. bcc over hcp vs bcc over bcc above), and minimize the difference between lattice constants, eg expressed as a percentage of mismatch. The material to be deposited over the tantalum layer also preferably has thermal expansion properties such that the difference in coefficient of thermal expansion (CTE) between the tantalum layer and the chosen metal is no greater than that exhibited by the alpha-tantalum/copper combination. Further preferred metals have the ability to form nitrides or have other properties indicative of electronic and/or chemical compatibility with alpha-tantalum. Additionally, for certain electrode applications, the material is selected for its ability to absorb hydrogen or deuterium in solution and/or form hydrides, or in some cases act as a diffusion barrier for hydrogen and/or deuterium.

With these considerations in mind, a first group of preferred materials for deposition on alpha-tantalum includes certain metals that exhibit a lattice constant mismatch of less than 11% relative to alpha-tantalum. Included in this group (group 1 copper substitutes) are the following metals:

Niobium (Nb): Lattice mismatch = 0.03%; Fermi (Fermi) energy difference = 0.12

β-titanium (Ti): lattice mismatch = 0.26%; Fermi energy difference = 0.20

Hafnium (Hf): Lattice mismatch = 3.15%; Fermi energy difference = 2.10

Tungsten (W): Lattice mismatch = 4.12%; Fermi energy difference = 0.60

Molybdenum (Mo): Lattice mismatch = 4.67%; Fermi energy difference = 0.70

Zirconium (Zr): Lattice mismatch = 5.72%; Fermi energy difference = 0.70

Nickel (Ni): Lattice mismatch = 6.75%; Fermi energy difference = 2.20

Erbium (Er): Lattice mismatch = 7.78%; Fermi energy difference = 0.70

Vanadium (V): Lattice mismatch = 8.22%; Fermi energy difference = 1.10

Dysprosium (Dy): Lattice mismatch = 8.84%; Fermi energy difference = 0.59

Samarium (Sm): Lattice mismatch = 9.68%; Fermi energy difference = 0.40

Gadolinium (Gd): Lattice mismatch = 10.14%; Fermi energy difference = 2.16

Neodymium (Nd): Lattice mismatch = 10.80%; Fermi energy difference = 0.29

Another group of preferred metals deposited on alpha-tantalum have a lattice constant mismatch of 11 to 21% relative to alpha-tantalum. These preferred metals generally have a bcc/ccp structure or where bcc/fcc/ccp/bct allotropes are known. Additionally, these metals are known to form nitrides. This group of metals (group 2 copper substitutes) includes the following metals:

Chromium (Cr): Lattice mismatch = 11.85%; Fermi energy difference = 1.72

Iron (Fe): Lattice mismatch = 13.17%; Fermi energy difference = 5.90

Cobalt (Co): Lattice mismatch = 14.28%; Fermi energy difference = 1.00

Rhodium (Rh): Lattice mismatch = 15.21%; Fermi energy difference = 1.10

Iridium (Ir): Lattice mismatch 16.29%; Fermi energy difference = 1.10

Rhenium (Re): lattice mismatch = 16.37%; Fermi energy difference =?

Osmium (Os): Lattice mismatch = 17.17%; Fermi energy difference = 1.10

Palladium (Pd): Lattice mismatch = 17.85%; Fermi energy difference = 0.90

Ruthenium (Ru): lattice mismatch = 18.04%; Fermi energy difference = 1.20.

Platinum (Pt): Lattice mismatch = 18.87%; Fermi energy difference = 0.70

It is believed that the above-identified Group 1 metals meet perhaps better, or fairly close, selection parameters, ie, those that characterize the copper/α-tantalum combination. It is also believed that the metals in Group 2 above satisfy parameters that fall only moderately outside the range provided by the copper/α-tantalum combination. Those of ordinary skill in the art will appreciate that these substitutes for copper can be incorporated into stable structures using various techniques known in the field of solid state physics, surface growth phenomena involving metals, and thin film processing and deposition techniques. These metals and techniques can be used without undue experimentation to produce electrodes or other structures with a metal interlayer from about 10 angstroms to several thousand angstroms thick consisting of TaN/α-Ta/M, where M is other than copper Metal. These preferred structures are thermodynamically stable over the temperature range used for operation and adhere strongly to silicon-based substrates. Also, preferred structures have diffusion barrier properties to prevent poisoning of the substrate by metal deposited on the alpha-tantalum.

Importantly, all of the preferred metals listed above in Groups 1 and 2 have structural allotropy, with the full range of their structural phase diagrams typically including several bcc, and/or ccb, and/or hcp structure. As will be recognized by those of ordinary skill in the art, these properties are taken into account in selecting appropriate thin film deposition techniques and conditions to induce growth in one of several alternative structural forms so that on top of the underlying α-tantalum layer Provides a stable structure. For example, some confirmed metals usually have hcp structure at room temperature, such as Co, Nd, Re, Os, and Ru. But one skilled in the art can first select one of these preferred materials and then use thin film deposition techniques and conditions suitable for manipulating film growth conditions to deposit bcc, fcc, ccp or other nearly matching pseudomorphic structures on top of α-tantalum . These and other design techniques can be used to minimize the effective lattice mismatch, produce sharp interfaces between metal layers, and achieve the desired stability in the finished construction.

The multilayer electrodes of the present invention may have any suitable shape. For example, they may include planar or curved structures provided on a single monolithic structure or on multiple structures such as spherical or other shaped pellets or beads. The electrodes are obtained by sequential deposition of multiple thin film layers of selected materials on an insulating, preferably silicon-containing substrate. In use, these electrodes are subjected to significant thermal and thermal cycling stresses, eg, due to resistive heating and/or exothermic reactions when current flows through the electrode material. Under typical operating conditions, the thin film electrodes of the present invention are expected to operate at about 100 degrees Celsius to about 300 degrees Celsius (when using an aqueous electrolyte), and about 300 degrees Celsius to about 1,000 degrees Celsius or higher (for other systems such as gas phase systems, molten salt electrolytes, Or operate at temperatures using "dry" electrolytes of solid metal hydrides).

Preferred electrodes of the present invention can also be configured such that significant interdiffusion of materials between thin film interfaces is avoided. For this reason, preferred electrodes are designed to avoid prolonged operation at temperatures above about 2/3 the melting point of the material with the lowest melting point in the thin film structure. Preferred metals for incorporation into thin film electrodes of the present invention have melting points greater than about 150 degrees Celsius, taking into account expected typical operating temperatures. This design feature is illustrated in the table below, which shows the subset of materials ideally used for multilayer thin film electrodes where a given maximum operating temperature is maintained.

Table 1 If the maximum expected sustained operating temperature of a commercial multilayer thin film electrode taught by the present invention is Any film material or substrate used for that particular electrode should then have a minimum melting point greater than or equal to about This in turn suggests the preferred thin film materials for multilayer electrodes designed for use at the maximum sustained operating temperature listed below 100°C 150°C Ag, Al, Au, Ba, Be, Ce, Co, Cr, Cu, Dy, Er, Fe, Gd, Hf, Ir, Mg, Mo, Nb, Nd, Ni, Os, Pd, Pt, Re, Rh, Ru, Sm, Ta, Th, Tl, Ti, U, V, W, Zr 200℃ 300℃ Ag, Al, Au, Ba, Be, Ce, Co, Cr, Cu, Dy, ErFe, Gd, Hf, Ir, Mg, Mo, Nb, Nd, Ni, Os, Pd, Pt, Re, Rh, Ru, Sm, Ta, Th, Tl, Ti, U, V, W, Zr 300℃ 448°C Ag, Al, Au, Ba, Be, Ce, Co, Cr, Cu, Dy, Er, Fe, Gd, Hf, Ir, Mg, Mo, Nb, Nd, Ni, Os, Pd, Pt, Re, Rh, Ru, Sm, Ta, Th, Ti, U, V, W, Zr 400°C 600°C Ag, Al, Au, Ba, Be, Ce, Co, Cr, Cu, Dy, Er, Fe, Gd, Hf, Ir, Mg, Mo, Nb, Nd, Ni, Os, Pd, Pt, Re, Rh, Ru, Sm, Ta, Th, Tl, U, V, W, Zr 500℃ 750°C Ag, Au, Be, Ce, Co, Cr, Cu, Dy, Er, Fe, Gd, Hf, Ir, Mo, Nb, Nd, Ni, Os, Pd, Pt, Re, Rh, Ru, Sm Ta, Th , Tl, U, V, W, Zr 600°C 900°C Ag, Au, Be, Co, Cr, Cu, Dy, Er, Fe, Gd, Hf, Ir, Mo, Nb, Nd, Ni, Os, Pd, Pt, Re, Rh, Ru, Sm, Ta, Th, Tl, U, V, W, Zr 700°C 1045°C Au, Be, Co, Cu, Dy, Er, Fe, Gd, Hf, Ir, Mo, Nb, Ni, Os, Pd, Pt, Re, Rh, Ru, Sm, Ta, Th, Ti, U, V, W, Zr 800℃ 1194°C Co, Cr, Dy, Er, Fe, Gd, Hf, Ir, Mo, Nb, Ni, Os, Pd, Pt, Re, Rh, Ru, Ta, Th, Ti, V, W, Zr 900°C 1343°C Co, Cr, Dy, Er, Fe, Hf, Ir, Mo, Nb, Ni, Os, Pd, Pt, Re, Rh, Ru, Ta, Th, Ti, V, W, Z 1000℃ 1493°C Co, Cr, Er, Fe, Hf, Ir, Mo, Nb, Os, Pd, Pt, Re, Rh, Ru, Ta, Th, Ti, V, W, Zr

In summary, the following factors are considered when selecting metals as copper substitutes for deposition on α-tantalum in the electrode structures of the present invention:

● According to the 2/3 M.P. rule, it is preferred to produce multilayer thin film electrodes that can operate at higher continuous operating temperatures than copper allows, and/or

preferably produce significantly different Fermi energies between the copper substitute materials and between the copper substitute material and the substrate, and/or

Absorption or "acquisition" of hydrogen and/or deuterium from solution by preferably maximizing or minimizing the thin film layer displacing copper over α-Ta, and/or

preferably create a barrier layer to prevent the diffusion of hydrogen atoms or ions to the tantalum layer immediately above the substrate, and/or

preferably promote the formation of metal hydrides in the copper substitute film layer "above" the tantalum under specific operating conditions and temperatures, and/or

Preferably optimize the copper substitute film layer to match the coefficient of thermal expansion of the "underlying" tantalum, and/or

• Optimizing the lattice structure and lattice constant matching to minimize the strain between the copper substitute layer and α-Ta. Identical or similar lattice structures and moderately similar lattice constants, as well as compatible chemistries and the use of various types of known thin film processing and deposition techniques can produce strong interactions between copper substitute materials and α-Ta Adhesion and as clear an interface as possible, while providing acceptable thermal stability over the expected continuous operating temperature range of the electrode.

Copper substitutes can be used as "intermediate layers" to allow other thin film materials to be deposited in the "upper" layers of the multilayer thin film structure contained by a given electrode, since otherwise these materials cannot be used with suitable adhesion for a particular application and adhesion directly onto tantalum or copper.

Copper substitutes enable the creation of multi-layered magneto-resistive spin valves (optional magnetic and non-magnetic thin-film layers such as Co/Pd or Co/Cu) or tunnel junctions (optional conductive magnetic and insulating non-magnetic thin-film layers) The ability of thin film electrodes.

With regard to the overall design of the multilayer electrode structures of the present invention, those skilled in the art recognize that some empirical experimentation may be required in selecting appropriate metals, deposition and processing techniques. At this point, those of ordinary skill in the art consider the following factors:

• Obtaining sharp interfaces between materials with as little alloying and/or interdiffusion as possible, ie trying to create abrupt interfaces between thin film layers.

• Attempt to minimize lattice mismatch and properly match lattice constants between thin film layers for compatible lattice structures (eg bcc to bcc versus bcc to hcp). All other things being equal, it is known that structural stability at thin-film interfaces is significantly more likely, though not certain, if the lattice mismatch at the interface is as small as possible, since this minimizes destabilization in adjacent thin-film layers chemical stress.

Attempt to make the chemical/electronic properties as consistent as possible between the materials (other things being equal, other metals that readily form nitrides like tantalum tend to be compatible with tantalum) to allow adhesion to alpha-tantalum The chemical aspect of sex is maximized.

Choose from a variety of different deposition, optional triggered growth modes, and processing techniques (e.g., choose between conventional sputtering versus molecular beam epitaxy for deposition, or vacuum annealing versus annealing between steps under gas) , which selects the appropriate technology for the particular combination of electrode material and application-specific requirements that achieve the desired result. For example, the use of known surfactants during surface film growth can enhance epitaxy and resulting adhesion.

Select combinations of thin film materials in a given electrode design to introduce other specific desired properties and/or requirements such as: melting point, Fermi energy difference, solubility of hydrogen and/or deuterium, electrical conductivity, coefficient of thermal expansion, ferromagnetism or antiferromagnetic magnetosphere.

• Select the combination of thin film materials with the most useful properties that together have sufficient thermal, structural, chemical, and thermodynamic stability over the expected sustained operating temperature range in a given electrode application.

The use of ultra-thin intermediate layers (so-called "buffer layers"; these layers can have a thickness from a few monolayers up to about 30 material atom monolayers) as required as a "working buffer" technique, which facilitates direct contact between each other An abrupt interface between certain thicker interlayers of other thin film materials (from about 100 angstroms up to a thickness of several thousand angstroms) that become less compatible at times. It is known, for example, that structural strain can be reduced by creating multilayer structures that introduce ultrathin compatible interlayers whose lattice constants lie between two other materials.

• Treat and/or polish electrode surfaces before, and/or during, and/or between deposition and film growth steps to control surface roughness, such that optimum surface smoothness is achieved.

To achieve these goals, those skilled in the art have a set of deposition and processing techniques at their disposal. For example, these can include:

● Sputtering deposition : and other types of physical vapor deposition (PVD), such as evaporation

● Chemical Vapor Deposition (CVD) : Including Low Pressure CVD, Plasma Enhanced CVD, Metal Organic CVD (MOCVD), Ultra High Vacuum CVD (UHV CVD), and Metal Organic Atomic Layer Deposition (MOALD)

Epitaxial deposition : Molecular Beam Epitaxy (MBE) such as Vapor Phase Epitaxy (VPE); MBE is particularly advantageous for metals such as Cu and the above-mentioned Cu substitutes, because MBE can provide heteroepitaxy at temperatures close to room temperature, so basically This eliminates the problem of interdiffusion at the film interface during electrode fabrication. An additional advantage is that many epitaxy techniques can achieve very high material growth rates.

• Electroplating or Electrodeposition (ED) : ED is a technique known especially well for copper, gold, and nickel and other precious metals. It is known that copper can be electroplated on top of a PVD copper seed layer.

● Electroless plating deposition : plating metal on metal through aqueous autocatalytic chemical reduction reaction, without the need for external current like electroplating. Operating temperatures are 30 to 80 degrees Celsius; coverage is insensitive to substrate geometry; and the process deposits dense films with little or no stress. Known to be particularly good for depositing metals such as Cu, Ni, Pd, Ni (on Al), Cu (Ni on Ti), Au, Rh, Ag, Co, and Fe.

Displacement plating deposition : After depositing a sufficiently thick layer of the first metal (such as copper) on the electrode, it is dipped in a layer containing a metal that is more noble than the deposited metal (copper) such as Ag, Au, Pt, Pd, Rh, Ir, Re, Os, and Ru dissolved ions in the bath. By simple dipping, the surface of the deposited metal (copper) film is dissolved (oxidized) and the selected metal is subsequently deposited (reduced) on top of the originally deposited metal (copper). The process is self-limiting, typically yielding deposited films only a few monolayers thick, ideal for triggering the pseudomorphic growth of thin films on metals with relatively large lattice mismatches.

Thermal growth or oxidation : the surface of the substrate is oxidized in an oxygen-rich atmosphere

Annealing : Improvement of film surface structural properties by heating, recrystallization, and cooling at various vacuum levels and/or under specific gases and air at various partial pressures and at elevated temperatures, thus reducing Lattice strain, control of grain size, control of statistical distribution of grain size, and improved properties of grain boundaries.

• Generation of thin films from metal alloy targets : This technique exploits the fact that PVD magnetron sputtering can deposit thin films on substrates with substantially the same composition as targets comprising simple or multi-element alloys. This can be used as a prudent fabrication technique to: (1) improve the effective lattice constant of thin films to reduce lattice constant mismatch compared to pure materials, and/or (2) in complex multilayer heterogeneous Thin film layers with special physical properties are produced in the structure. Vegard's law can be used as an approximation when changing the effective lattice constant through the judicious use of an alloy target, and it has the following form for a binary alloy of metals A and B: a ₀ (x) = a _A (1-x) + a _B x, where a ₀ (x) is the lattice constant of A _1-x B _x . For ternary alloys, the equation expressing Vegard's law uses simple linear interpolation to obtain the more complex form described by Herman, MA in "Silicon-Based Heterostructures: A Study by Molecular Beam Epitaxy" along with supporting references. "Strained Layer Growth" (Silicon-Based Heterostructures: strained-Layer Growth by Molecular Beam Epitaxy), Cryst. Res. Technol. , 34, 1999, 5-6, 583-595. In many cases, the predicted effective lattice constants deviate from the law by small amounts, ie on the order of about 3%. Regarding special physical properties: For example, for certain applications of the present invention, it may be desirable to incorporate an "upper" film layer with special magnetic or electronic properties. Examples of these alloys are: cobalt/rhenium bilayer (giant magnetoresistance); NiFe, CoFe, CoZrTa, CoNb, CiZrNb, FeAl, FeTa, and FeZr (ferromagnetic); PtMn (antiferromagnetic); CoPt and FePt (large isotropy constant); UAl ₂ (a previous type of nuclear reactor fuel); U ₆ Fe, UPt ₃ , CePd ₃ , and various related heavy electron compounds (for an excellent overview see: Degiorgi, L., "Heavy Electron Compounds The electrodynamic response of heavy electron compounds" (The electrodynamic responses of heavy electron compounds), Reviews of Modern physics, 1999, 71, 3, 687-734). Additionally, spin-valve structures can be incorporated into the "upper" layers of the electrodes of the present invention, these structures consisting of pairs of ferromagnetic layers (such as Co) separated by non-magnetic conductive films (such as Cu or Pd), in the present invention An intermediate Co/Cu/Co/Cu... or Co/Pd/Co/Pd... structure is produced in the "upper" layer of the electrode taught. These spin valve structures can be incorporated into electrodes using the methods disclosed herein for material selection, deposition, and processing. A spin valve or any other layered structure with specific properties may comprise some or all of the "upper" layers of the electrodes taught by the present invention. Ion implantation and/or rapid solidification can also be used to create unusual alloys containing "...nanoscale inclusions of elements [normally] insoluble in the matrix". This technique can be used to fabricate electrodes using metals that form relatively few compatible pairs with other metals. These metals include: Be, Ce, Mg, Th, and Tl. As an example of the application of this technique, it is known that thallium (Tl is usually hcp) can be implanted into aluminum (Al) as sub-10 nm inclusions with an fcc structure with an aluminum matrix (see: Johnson, E., " Multiphase and Multicomponent Nanoscale Inclusions in Aluminum (Multiphase and Multicomponent Nanoscale Inclusions in Aluminum), Philosophical Magazine Letters , 1993, 68, 131-135).

• Heteroepitaxial multilayer growth : Broadly speaking, this electrode thin film fabrication technique involves deliberate triggering of strain and/or pseudomorphic growth during deposition. For any two metals A and B, epitaxial growth of B on top of A can produce strained and/or pseudomorphic regions where B has the in-plane lattice spacing of A. Elastic energy builds up to a critical thickness for plastic relaxation, often accompanied by a change in growth mode. By choosing appropriate deposition techniques to control the volume fraction and/or total thickness (measured in atomic monolayers) of each of the A and B layers, the different structural phases of the copper substitute materials (groups 1 and 2 above) can be stabilized. Known examples of these strained or pseudomorphic structural transitions include hcp to bcc (in Zr), bcc to hcp (in Nb), fcc to hcp (in Al), and hcp to fcc (in Ti). For example, it is known that fcc of Ti can successfully grow up to 5 monolayer thick films on fcc of Al(100) surfaces despite a "nominal" lattice mismatch of 22% (see: Smith, RJ et al., "Growth of thin Ti films on Al single-crystal surfaces at room temperature" (Growth of thin Ti films on Al single-crystal surfaces at room temperature), Surface and Interface Analysis 1999, 27, 185). As another example, it is known that Fe can be deposited on top of Au(111) surfaces. Experimental data indicate that the first three monolayers of Fe grow as fcc structures on the Au(111) surface, followed by transformation to bcc structures in the other "upper" layers of Fe. These examples illustrate that a fabrication technique in which the preferred copper substitute thin film material is deposited on top of α-Ta can be controlled in a predictable manner by controlling the number of atomic monolayers superimposed on the α-Ta surface and subsequent accumulation Enough monolayers are manipulated to stop deposition before changing the pseudomorphology or strained structure.

• Use of atomic surfactants : This technique uses a third atomic species (not deposited on the surface, or introduced into the surface) for regulating the growth of a metal B deposited on top of another metal A. Properly selected surfactants promote surface "wetting" and ordered 3D layer-by-layer growth of the metal being deposited on the A surface rather than the formation of 2D and 3D "islands" (Volmer-Weber growth). If possible, it is best to avoid islanding during deposition and surface growth, as it can lead to strain-enhanced diffusion (reducing the "sharpness" of the interface between A and B) and/or to create defects and dislocations, which would Weaken structural integrity and adhesion at interfaces. Surfactants achieve their effect by lowering the surface energy of A and B during the deposition process. This technique is well described by Herman, MA in the paper "Silicon-Based Heterostructures: Strained-Layer Growth by Molecular Beam Epitaxy" Cryst. Res. Technol., 34, 1999, 5-6, 583-595.

Other aspects of the invention relate to electrode configurations comprising a copper layer (optionally itself on top of the tantalum nitride/a-tantalum combination) and at least one and preferably several metal layers deposited on top of the copper layer. Similar to the selection of copper substitutes as disclosed above, one skilled in the art may consider the following factors when selecting a metal for deposition over copper:

● the preferred material can be deposited as a thin film by some known deposition techniques and methods, and

the candidate material preferably has a melting point greater than 150 degrees Celsius, and

Candidate materials selected to minimize differences between lattice structure species (eg, bcc on hcp versus bcc on bcc), and differences in relative values of lattice constants expressed as a percentage of misfit compared to copper, and

the candidate material for deposition over copper preferably does not have a difference in coefficient of thermal expansion ("CTE") compared to copper that is greater than the difference in CTE between alpha-tantalum and copper, and

Preferable materials are capable of nitride formation, exhibit some chemical compatibility with copper, and

• In some electrode applications, it is desirable for candidate materials to be able to absorb hydrogen/deuterium in solution and/or form hydrides, or act as a diffusion barrier for hydrogen/deuterium.

Using the above criteria, the following metals constitute a preferred group for deposition on copper exhibiting a lattice constant mismatch of less than 11%. Also in each case these metals are generally known to be of bcc/ccp structure or bcc/fcc/ccp/bct allotrope and these metals are known to be capable of forming nitrides. In the enumeration below (Group I), the lattice mismatch percentages and Fermi energy differences are given relative to copper.

Samarium (Sm): Lattice mismatch = 0.17%; Fermi energy difference = 1.40

Gadolinium (Gd): Lattice mismatch = 0.58%; Fermi energy difference = 0.36

Dysprosium (Dy): Lattice mismatch = 0.61%; Fermi energy difference = 1.21

Neodymium (Nd): Lattice mismatch = 1.19%; Fermi energy difference = 1.51

Erbium (Er): Lattice mismatch = 1.57%; Fermi energy difference = 1.10

Nickel (Ni): Lattice mismatch = 2.51%; Fermi energy difference = 0.40

γ-uranium (U): lattice mismatch = 4.01%; Fermi energy difference = 3.50

Thallium (Tl): Lattice mismatch = 5.21%; Fermi energy difference = 1.15

Rhodium (Rh): Lattice mismatch = 6.75%; Fermi energy difference = 0.70

Iridium (Ir): Lattice mismatch = 6.20%; Fermi energy difference = 0.70

Palladium (Pd): Lattice mismatch = 7.63%; Fermi energy difference = 0.90

β-titanium (Ti): lattice mismatch = 8.43%; Fermi energy difference = 1.60

Platinum (Pt): lattice mismatch = 8.56%; Fermi energy difference = 1.10

Niobium (Nb): Lattice mismatch = 8.70%; Fermi energy difference = 1.68

Likewise, using the reasons above and selecting metals with a lattice constant mismatch of 11% to 21% relative to copper, the following metals constitute the second preferred group (Group II) for deposition on top of copper:

Magnesium (Mg): Lattice mismatch = 11.22%; Fermi energy difference = 0.08

Hafnium (Hf): Lattice mismatch = 11.58%; Fermi energy difference = 0.30

Aluminum (Al): Lattice mismatch = 12.02%; Fermi energy difference = 4.70

Gold (Au): Lattice mismatch = 12.82%; Fermi energy difference = 1.87

Molybdenum (Mo): Lattice mismatch = 12.94%; Fermi energy difference = 1.10

Silver (Ag): Lattice mismatch = 13.01%; Fermi energy difference = 1.51

Vanadium (V): Lattice mismatch = 16.18%; Fermi energy difference = 0.70

Iron (Fe): Lattice mismatch = 20.70%; Fermi energy difference = 4.10

As disclosed above, the working electrode preferably comprises a plurality of thin metal films, comprising at least two different kinds of metals. These multilayer working electrodes can be relatively simple or relatively complex, and are advantageously characterized by a specific sequence of thin metal layers. The particular set or sequence of thin metal layers chosen for the working electrode depends on several factors including, for example, the overall physical, electrochemical, and electronic properties desired for a particular electrode application. Factors considered in this regard include the need to withstand specific sustained operating temperatures, the need to maximize hydrogen or deuterium loading rates or levels, resistance to hydrogen embrittlement, the introduction of intermediate ferromagnetic or antiferromagnetic layered structures, intermediate heavy electrons The introduction of structure, and similar factors. Using these and other parameters, the following table gives the expected preferred metal-metal combinations. In particular, the left column of the table gives a given metallic material, the middle column gives the first set of metallic material combinations in which the percentage mismatch of lattice constants between the two metals is below 11%, and the right Columns give the second group of metals where the lattice constant mismatch between the two metals is 11% and 21%.

Table 2 preferred material Number of pairs (I, II, sum) Combination with preferred material group I (blue on the diagram) Group II combination of preferred materials (ochre on the picture) Ag (silver) (4, 9, 13) Al, Au, Pd, Pt, Cu, Dy, Er, Gd, Nd, Ni, Sm, Tl, γ-U Al (aluminum) (2, 3, 5) Ag, Au Cu, Tl, γ-U Gold (Au) (6, 10, 16) Ag, Al, Ir, Pd, Pt, Rh Cu, Dy, Er, Gd, Nd, Ni, Sm, Th, γ-U, Zr Be (beryllium) (0, 3, 3) none Os, Re, Ru Ce (Cerium) (1,0,1) Th none Co (cobalt) (6,6,12) Cr, Fe, Os, Re, Ru, V Hf, Mo, Nb, α-Ta, β-Ti, W Cr (chromium) (9,6,15) Fe, Hf, Mo, Os, Re, Ru, V, W Nb, α-Ta, Ti, Tl, γ-U, Zr Cu (copper) (16, 6, 24) Dy, Er, Gd, Ir, Nb, Nd, Ni, Pd, Pt, Rh, Sm, α-Ta, β-Ti, Tl, γ-U, Zr Ag, Al, Au, Hf, Mg, V Dysprosium (Dy) (15, 6, 21) Cu, Er, Gd, Ir, Nb, Nd, Ni, Pd, Pt, Rh, Sm, α-Ta, β-Ti, γ-U, Zr Ag, Au, Hf, Mo, V, W Erbium (Er) (16, 6, 22) Cu, Dy, Gd, Ir, Mg, Nb, Nd, Ni, Pd, Pt, Rh, Sm, α-Ta, β-Ti, γ-U, Zr Ag, Au, Hf, Mo, V, W Fe (iron) (8, 4, 12), Co, Cr, Mo, Os, Re, Ru, V, W Hf, Nb, α-Ta, β-Ti Gadolinium (Gd) (15, 6, 21) Cu, Dy, Er, Ir, Nb, Nd, Ni, Pd, Pt, Rh, Sm, α-Ta, β-Ti, γ-U, Zr Ag, Au, Hf, Mo, V, W Hafnium (Hf) (9, 12, 21) Cr, Mo, Nb, Ni, α-Ta, β-Ti, V, W, Zr Co, Dy, Er, Fe, Ir, Gd, Nd, Os, Re, Rh, Ru, Sm Ir (iridium) (12, 4, 16) Au, Cu, Dy, Er, Gd, Nd, Ni, Pd, Pt, Rh, Sm, Zr Mo, Nb, α-Ta, β-Ti Mg (Magnesium) (2,1,3) Tl, γ-U Cu Mo (molybdenum) (9, 11, 20) Cr, Fe, Hf, Nb, α-Ta, β-Ti, V, W, Zr Co, Dy, Er, Gd, Nd, Ni, Os, Re, Rh, Ru, Sm Nb (niobium) (14, 9, 23) Cu, Dy, Er, Gd, Hf, Mo, Nd, Ni, Sm, α-Ta, β-Ti, V, W, Zr Co, Cr, Fe, Ir, Os, Pd, Pt, Re, Rh Nd (neodymium) (21, 6, 27) Cu, Dy, Er, Gd, Nd, Ni, Pd, Pt, Rh, Sm, Ir, Nb, Ni, Pd, Pt, Rh, Sm, α-Ta, β-Ti, γ-U, Zr Ag, Au, Hf, Mo, V, W Ni (nickel) (15, 6, 21) Cu, Dy, Er, Gd, Hf, Ir, Nb, Nd, Pd, Rh, Sm, α-Ta, β-Ti, γ-U, Zr Ag, Au, Mo, Pt, V, W Os (Osmium) (6,6,12) Co, Cr, Fe, Re, Ru, V Be, Mo, Nb, α-Ta, W, Zr Pd (palladium) (12, 5, 17) Ag, Au, Cu, Dy, Er, Gd, Ir, Nd, Ni, Pt, Rh, Sm Nb, α-Ta, β-Ti, γ-U, Zr Pt (platinum) (11, 6, 17) Ag, Au, Cu, Dy, Er, Gd, Ir, Nd, Pd, Rh, Sm Nb, Ni, α-Ta, β-Ti, γ-U, Zr Re (rhenium) (6,7,13) Co, Cr, Fe, Os, Ru, V Be, Hf, Mo, Nb, α-Ta, β-Ti, W Rh (rhodium) (13, 6, 19) Au, Cu, Dy, Er, Gd, Ir, Nd, Ni, Pd, Pt, Sm, γ-U, Zr Hf, Mo, Nb, α-Ta, β-Ti, W Ru (ruthenium) (5, 6, 11) Co, Cr, Fe, Os, Re Be, Hf, Mo, Nb, V, W Samarium (Sm) (13, 4, 17) Cu, Dy, Er, Gd, Nb, Nd, Ni, Pd, Pt, Rh, Ru, β-Ti, Zr Hf, Mo, V, W α-Ta (tantalum) (14, 9, 23) Cu, Dy, Er, Gd, Hf, Mo, Nb, Nd, Ni, Sm, β-Ti, V, W, Zr Co, Cr, Fe, Ir, Os, Pd, Pt, Re, Rh Th (thorium) (1,1,2) Ce Au β-Ti (titanium) (15, 8, 23) Cu, Dy, Er, Gd, Hf, Mo, Nb, Nd, Ni, Sm, α-Ta, γ-U, V, W, Zr Co, Cr, Fe, Ir, Pd, Pt, Re, Rh Tl (thallium) (3, 2, 5) Cu, Mg, γ-U Ag, Al γ-U(uranium) (10, 6, 16) Cu, Dy, Er, Gd, Mg, Nd, Ni, Rh, β-Ti, Tl Ag, Al, Au, Pd, Pt, V V (vanadium) (11, 10, 21) Co, Cr, Fe, Hf, Mo, Nb, Os, Re, α-Ta, β-Ti, W Cu, Dy, Er, Gd, Nd, Ni, Ru, Sm, γ-U, Zr W (tungsten) (9, 11, 20) Cr, Fe, Hf, Mo, Nb, α-Ta, β-Ti, V, Zr Co, Dy, Er, Gd, Nd, Ni, Os, Re, Rh, Ru, Sm Zr (zirconium) (14, 6, 20) Dy, Er, Gd, Hf, Ir, Mo, Nb, Nd, Ni, Rh, Sm, α-Ta, β-Ti, W Au, Cr, Os, Pd, Pt, V

Based on the teachings herein, one skilled in the art selects the above metal combinations while taking into account other factors disclosed herein, including, for example, the presence of structural allotropes as needed to produce stable membrane structures. Also, for Table 2 above, if iron is used, it is preferably a reduced activation martensitic (RAM) F82H steel comprising 7 to 10% Cr.

When considering the choice of metal combinations for thin film layers, the total number of combinations providing lattice constant mismatches below 21%, and the total number of combinations providing lattice constant mismatches below 11%, may also depend on specific metal considerations. total, and the total number of combinations providing lattice constant mismatches between 11% and 21%. Table 3 below ranks the selected metals in this manner.

table 3 Number of the preferred combination Total number of preferred combinations Total number of Group I preferred combinations Total number of Group II preferred combinations 27 Nd none none 26 none none none 25 none none none twenty four Cu none none twenty three Nb, α-Ta, β-Ti none none twenty two Er none none twenty one Dy, Gd, Hf, Ni, V Nd none 20 Mo, W, Zr none none 19 Rh none none 18 none none none 17 Pd, Pt, Sm none none 16 Au, Ir, γ-U Cu, Er none 15 Cr Dy, Gd, Ni, β-Ti none 14 none Nb, α-Ta, Zr none 13 Ag, Re Rh, Sm none 12 Co, Fe, Os, Ir, Pd f 11 Ru Pt,V Mo, W 10 none γ-U Au, V 9 none Cr, Hf, Mo, W Ag, Nb, α-Ta 8 none Fe β-Ti 7 none none Re 6 none Au, Co, Os, Re Co, Cr, Cu, Dy, Er, Gd, Nd, Ni, Os, Pt, Rh, Ru, γ-U, Zr 5 Al, Tl Ru PD 4 none Ag Fe, Ir, Sm 3 Be, Mg Tl Al, Be 2 Th Al, Mg Tl 1 Ce Ce, Th Mg, Th 0 none be Ce

As can be seen from Table 3 above, neodymium forms more Group I combinations (lattice constant mismatches below 11%) than any other identified metal. Both copper and erbium form the second largest number of Group I combinations, highlighting the advantage of copper as a layer (including the underlying base layer) in thin film structures.

Regarding the total number of combinations (group I plus group II), neodymium is preferred, followed by copper, which includes niobium, alpha-tantalum, and beta-titanium. There is also a large class of 14 elements that form 6 Group II combinations.

Additionally, with regard to the total number of combinations (Group I plus Group II), the identified selected metals were sorted into two wide sets separated by a relatively wide gap (6 to 10 combinations in total). Thus, with respect to total combinations, those metals identified in Table 3 above that appear in the first set with 9 or more total combinations (Group I + Group II) form another group for use in the present invention. Preferred group of materials.

In some cases, electrodes of the present invention may be loaded with hydrogen isotopes, such as hydrogen, deuterium or tritium, when used in electrochemical cells or elsewhere. In these applications, typically up to 100 atomic percent hydrogen/metal (for some transition metals) and as high as 200 to 300 atomic percent hydrogen/metal (for materials such as thorium) and rare earth metals such as The electrodes were operated at steady-state hydrogen/metal loading ratios of cerium and neodymium). Hydrogen loading typically involves the dissociation of hydrogen or deuterium molecules on the metal surface, followed by exothermic or endothermic dissolution of hydrogen or deuterium atoms, and diffusion as a solid solution to interstitial sites within the metal lattice. Then, a distinct metal hydride phase forms. Such deliberate electrochemical loading of hydrogen or deuterium or tritium into the thin film lattice of the electrodes of the invention can affect the structural, electronic and thermodynamic stability of multilayer thin film electrodes, especially at the intermetallic interface.

For example, for many metals, within any given structural phase, the lattice constant tends to increase in parallel (eg, approximately linearly) at high hydrogen or deuterium loading ratios. In some cases, however, the value of a given metal's lattice constant can change relatively abruptly if a certain structural phase shift point is reached, for example, at the onset of hydride formation. Therefore, if adjacent metal layers have significantly different solubilities/diffusivity and different phase diagrams in terms of hydrogen isotope uptake, structural problems may arise at the metal interface. For example, problems may arise if the otherwise properly matched lattice constants of two different metals at the film interface change at completely different rates during the loading process. This ultimately leads to an unacceptably high lattice constant mismatch, which in turn may compromise the adhesion and stability of the film interface when the desired steady-state hydrogen/metal ratio and temperature are reached.

Table 4 below gives the calculated percent change in the total volume of the metal due to an increase in the lattice constant for a hypothetical cubic lattice structure. These values can be used by those skilled in the art as a guideline in evaluating the metals incorporated in the working thin film electrodes of the present invention.

Table 4 Percent increase in lattice constant a Percent increase in total volume of the structure 1% 3% 2 5 3 9 4 12 5 16 6 19 7 twenty three 8 26 9 30 10 33 11 37 12 40

As mentioned above, hydrogen loading can also cause significant changes in the structural space group and/or lattice packing arrangement of the metal. These changes can significantly affect the adhesion and stability of the film interface.

Hydrogen isotope and metal loading can also cause embrittlement in some cases, which includes a marked decrease in the structural integrity of a particular metal, sometimes manifested by the appearance of macroscopic stress-related cracks, void formation, blistering, or along the grain Boundary cracked. Loss of mechanical strength and structural failure may occur.

The lattice constant change produced by a given level of hydrogen isotope loading can be determined empirically or estimated from data for other similar metals. For most metals, _the percent increase in the lattice constant of the simpler hydrides of the form _MyHx is expected to be substantially no more than about 4% to 7% at loading ratios that ultimately saturate at values well below 1.5 value. This range includes the largest possible hydrogen isotope/metal ratio for many of the preferred metals herein, including seven of eight phases of palladium (with a hydrogen/metal ratio of about 1 at maximum loading), titanium, and niobium. The delta-phases of niobium and zirconium are maximized at hydrogen/metal ratios close to 2. As for more complex hydrides, the lattice constant can increase nonlinearly at hydrogen isotope/metal loading ratios exceeding about 1.2, for example, in the case of certain hydrides of the form M1 _y M2 _z H _x , where M ₁ and _M2 is metal.

In summary, in order to moderate the possible negative effects of hydrogen isotope loading, those skilled in the art may consider the following factors.

1. For each metal under consideration, one of ordinary skill in the art can examine the following data:

Hydrogen/deuterium solubility/permeability/diffusion at various temperatures, coefficient of thermal expansion ("CTE"), phase diagrams for M/H or M/D ratios, desired crystallinity induced intentionally during film deposition lattice structure, and lattice constants related to the structure of the material prior to hydrogen loading, and subsequently

2. Select the particular combination of Group I and Group II metals at the interface such that: independently before meeting other design goals such as maximizing the difference in Fermi energy between the thin film layers of the electrode, will have significantly higher A material with an affinity for dissolving hydrogen and/or forming a hydride is combined with a different preferred material in the adjacent thin film layer (on either side of the interface), which preferably has: (a) a lower affinity for The affinity for dissolving hydrogen/deuterium and/or forming hydrides, and (b) is significantly greater than for metals with a higher propensity to dissolve hydrogen and/or form hydrides (i.e., for many other combinations of preferred metals , on the order of at least 3% to 6% greater) lattice constant before H or D loading, and additionally if possible, (c) not worse than, almost equal to but preferably greater than with larger dissolved hydrogen and/or CTE of preferred materials with a propensity to form hydrides. This approach enables the selection of preferred materials and their combination in such a way that the relative lattice mismatch (based on structural factors and CTE) between adjacent thin film layers is not significantly worse and in some cases when the materials reach The electrochemical cell is actually improved (i.e., the percent mismatch is decreased) when undergoing dynamic hydrogen and/or deuterium loading in the electrochemical cell during the target operating temperature, and subsequently

3. Determine the possible range of operating temperatures for a given electrode design. Examine the degree of synchronization in temperature between adjacent film layers of the preferred material. Based on this analysis, a final list of preferred combinations of additionally preferred materials was generated that minimizes relative structural changes between film layers affected by temperature and pressure.

Following Fig. 2 and 3 and table 5 have given the hydrogen solubility and the hydrogen permeability of the selected preferred material for the working electrode layer of the present invention, and have illustrated that those skilled in the art can prepare the multilayer thin film electrode of the present invention. The type of data used.

table 5

Hydrogen Transport Rates Through Various Coating Materials at 1200°F coating material Diffusion, cm ² /sec 100Hr thickness, penetration value, cm Permeability, mols/secm(Pa) ^1/2 Pt 2.3e-04 22.0 1.2e-11 Au 2.8e-05 7.7 3.3e-13 Cu 5.6e-05 11.0 2.0e-11 W 1.5e-04 18.0 7.7e-15 Ag 4.7e-05 10.1 2.7e-12 Ni 3.5e-05 8.7 3.1e-10

From: "Environmental Effects on Advanced Materials-III-Al Alloys", Dr. Russell D. Kane

As an illustrative use of the above factors in making electrodes, copper has a relatively low affinity for dissolving hydrogen and deuterium and for forming hydrides, and a relatively high coefficient of thermal expansion (17.5). Therefore, it is preferred to deposit metals directly on top of copper that are loaded with hydrogen or deuterium to a ratio of hydrogen/deuterium to metal relatively higher than that of copper, have a lattice constant that is lower than that of copper before loading, and have a lower lattice constant than that of copper. coefficient of thermal expansion. Under these criteria, preferred metals for deposition over copper include niobium, nickel, tantalum, titanium, vanadium, and zirconium.

As disclosed above, in certain electrodes of the present invention, tantalum is incorporated into an adhesive or base layer. Tantalum is known to become brittle easily when loaded with hydrogen isotopes. According to another aspect of the invention, these tantalum-containing layers are protected against hydrogen embrittlement by overlying layers resistant to the diffusion of hydrogen isotopes. In a first embodiment, the tantalum-containing layer is protected by a layer of oxygen-free copper (also known as electronic-grade or magnetron-grade oxygen-free copper). Suitable sources of such copper include, for example, Mitibishi Materials Corporation, whose trade descriptions are "MOF for Magnetron" and "MOF for Superconductivity". Another oxygen-free copper is a zirconium oxygen-free copper alloy developed by Thatcher Alloys, Ltd., United Kingdom and sold as "Outokunpu Zirconium copper Zrk015" (zirconium content 0.15%). As an alternative to oxygen-free copper in this environment, copper substitutes from the above disclosure (for coating on tantalum) can be selected based on their relative solubility, permeability, affinity and embrittlement for hydrogen . For the preferred metals, these values are not significantly higher, and preferably lower than those for copper. For example, using these criteria, molybdenum and tungsten are preferred metals for forming barrier layers to protect tantalum from hydrogen embrittlement, and having a lattice constant mismatch with alpha-tantalum of less than 11%. Iridium, osmium, platinum, rhenium, and rhodium constitute a second group of preferred metals for forming this protective layer while having a lattice constant mismatch of 11% to 21% relative to alpha-tantalum.

If it is desired to achieve a stable interface with alpha-tantalum, a hydrogen embrittlement protection material can be applied to alpha-tantalum using displacement plating deposition. For example, an ultrathin layer of copper can be deposited first on top of α-tantalum using techniques such as PVD, CVD, MVE, or VPE. This copper ultra-thin layer can then be removed and replaced with the selected metal deposited by displacement plating. The resulting ultrathin layer of metal is used as a seed layer for depositing additional atomic monolayers of the selected metal by techniques of PVD, CVD, MVE, VPE, electroless plating, or electroplating thin film deposition methods. The remainder of the electrode structure can then be fabricated as described herein.

It will be appreciated that if hydrogen embrittlement is not a problem (eg, hydrogen isotope loading is not encountered in use), the choice of layer to be deposited on the alpha-tantalum need not limit aspects such as hydrogen diffusivity or permeability.

On the other hand, if maximum protection of the underlying tantalum-containing layer is desired, two or more layers of the same or different protective metals may be deposited on top of the tantalum-containing layer. Illustratively, in addition to the copper layer (standard or oxygen-free copper), one or more layers selected from the hydrogen diffusion/permeation resistant metals disclosed above for deposition on copper may be used. For example, iridium, platinum, and rhodium are relatively resistant to hydrogen permeation/diffusion, and have a lattice constant mismatch of less than 11% relative to copper. As other examples, gold, molybdenum, silver, and tungsten have a lattice constant mismatch of 11% to 21% relative to copper, and are relatively resistant to hydrogen permeation/diffusion. In the overall electrode design, those skilled in the art will understand that other factors in metal selection may include maximization of the Fermi energy difference between film layers (preferably exhibiting a Fermi energy difference greater than about 0.5, more preferably greater than about 1) , minimization of interdiffusion, and other factors taught herein.

Another feature of the present invention involves mitigating deleterious electromigration effects that can occur within multilayer thin film electrodes. These moderations help maximize the durability, stability, and lifespan of the electrodes operating under normal conditions. As a first example, the present invention, as described above, protects the copper or copper substitute from diffusing into the insulating substrate where it could react with and poison the insulating substrate. According to the present invention, the electrical diffusion can be improved by using a tantalum nitride/a-tantalum layer bonded to a silicon-based substrate. These tantalum-containing layers are resistant to copper diffusion.

Another type of electromigration to be mitigated comes from the current-induced physical transport of conductive materials within the electrode thin film layer due to the direct force of the voltage gradient on the ions, and/or the direct transfer between moving electrons and atoms/ions momentum. This unwanted net physical flow of material can cause material to be consumed "upwind" and accumulated "downwind" in the film layers, forming voids (upwind) and hillocks (downwind) in the film.

It is known that species transport associated with electromigration occurs predominantly along metal grain boundaries up to about 50% of the melting point of any given material. Both forces are expected to exist for protons or tritons containing mobile ionic species in the case of multilayer thin film electrodes.

A relatively more serious problem from electromigration occurs because of electron winds and migrating ions at the intersection of three grain boundaries (called the "triple point"). Atoms/ions gather at the intersections of these grain boundaries to form hillocks.

In the case of multilayer thin-film electrodes operating in wet electrochemical cells, then in addition to the above-mentioned solid-state electromigration, there is another electromigration effect called electrolyte electromigration.

Another phenomenon in electromigration is called thermal self-acceleration. In this phenomenon, the increase of temperature, the growth of voids, the increase of local current density, and the increase of Joule heating all participate in the accelerated electromigration process. Additional information on these aspects of electromigration can be found in Chang, Jing, "Electro-Migration and Related Integrated Circuit Failure", July, 2001 (Materials Engineering Department, Drexel University, PA).

The operating conditions of the electrodes of the present invention are expected to exhibit the potential to ameliorate the deleterious effects of electromigration. Preferred operation includes a minimum current density of about 10 ² to about 10 ⁵ A/cm ² . Typical operating temperatures are a minimum of 100 degrees Celsius, and can be as high as 1,000 degrees Celsius or more. In some instances, the operating temperature is from about 100 degrees Celsius to about 500 degrees Celsius, more typically from 100 degrees Celsius to 300 degrees Celsius. Preferred multilayer thin film electrodes of the present invention are also expected to have useful operating life times of 5,000 to 100,000 hours.

Under these operating conditions, excess electromigration can locally disrupt sharp interfaces between different metal layers, creating hillocks that introduce additional stress in the thin film lattice structure, which can compromise adhesion between layers and/or enable The physical and electronic integrity of the thin film structure is unstable, and/or produces a large number of voids that can cause localized unloading of hydrogen isotopes in the form of voids, and/or compromise the strength and integrity of the adhesion and overall thin film structure.

According to the invention, in order to moderate these deleterious effects, it is possible to introduce thin film layers having a relatively large average grain size relative to the layer thickness. The utilization of this relatively large grain size relative to the layer thickness can produce a cross-sectional grain pattern known as bamboo or bamboo-like structure. Preferably, the dimensions of the average grain size of these bamboo grain structures are at least as thick as the layer into which the structure is introduced. These bamboo grain patterns are expected to maximize the stability, functional integrity, and operational lifetime of the multilayer thin film electrodes of the present invention. Specifically, these grain patterns provide the following benefits:

• The highest possible percentage of grain boundaries within a layer tends to be oriented perpendicular or highly inclined to the electromigration path ("proper" grain boundary alignment), rather than parallel to it ("inappropriate" alignment). This suitable alignment minimizes the overall electromigration flux that strongly favors parallel flow along the main electron and ion flow axes within the thin film layer.

• The average geometric relationship between grain intersections minimizes the number of triple points that occur in thin film layers.

The average density (or in other words, the total surface area) of the grain boundaries within the thin film layer is significantly reduced; all other things being equal, because the total surface area associated with the grain boundaries decreases, the electromigration flux also decreases, which is related to the decrease in the grain boundary area unanimous.

• Inevitably, a certain percentage of grain boundaries are interconnected in almost the same plane and/or parallel to the electromigration path of the standard type. With bamboo grain patterns, these kinds of improper grain boundary alignments and in-plane connections do not travel long distances through thin film layers, but instead end up encountering vertical or highly inclined bamboo grain boundaries. At this point, a back stress gradient develops to slow or prevent further migration and tends to push the transported material back in the opposite direction. In addition to vacancy concentration gradients and temperature cycling, if the current is altered in some way, for example using A/C or pulsed D/C, or stopped, this effect can help partially restore electromigration-induced defects.

Preferably, for each thin film layer in the working electrode, one of ordinary skill can control the total thickness of each of these thin film layers (in terms of the number of atomic monolayers containing it) in combination with deposition and annealing techniques such that the average grain size of the layer has Make sure to create the desired physical dimensions of the bamboo grain pattern in this layer. At this point, the thin film layer forms the working electrode whose geometry is like a flat quasi-two-dimensional sheet, or like a more complex quasi-two-dimensional sheet with regions of various positive and/or negative curvatures. The preferred bamboo-type grain patterns are preferably deposited and oriented so that they are as close as possible to perpendicular (or highly inclined) to the main direction of current and/or ions through the working thin film layer.

In this regard, control over the average grain size of each working layer, the inclination of the grain boundaries, and the tightness of the grain size distribution around the median can be achieved in a number of ways including, for example, selection of an appropriate deposition method. Illustratively, for some metals, electroplating and electroless deposition are preferred over various sputtering methods. This is because, for certain metals, electroplating or electroless plating is known to produce significantly larger grain sizes than can be deposited by sputtering techniques. By starting with a larger grain size during the initial deposition step, the amount of annealing required to achieve the desired final average grain size and tight size distribution can be eliminated or reduced. Additionally, subsequent annealing and patterning steps can be used to control grain size and grain size distribution. Annealing temperature, hold time at a particular temperature ("dipping"), and cooling rate are specific process parameters uniquely determined for a given metal.

Electromigration damage can also be controlled by maximizing heat dissipation from the working layer of the thin film electrode. This, in turn, can be achieved by a combination of (a) controlling the overall thickness of the working layers of a thin-film multilayer electrode, (b) selecting a substrate that can help conduct heat through the "base layer" of the electrode, (c) selecting a substrate with properties that help Barrier layer materials with physical properties that facilitate heat conduction from the thin film working layer, and (d) use of macroscopic electrode and electrochemical cell geometries that maximize heat transfer from the thin film working layer to the electrolyte and/or other features integrated with the cell a radiator.

Regarding the substrate and heat transfer, _SiO2 is not as thermally conductive as pure Si at the operating temperatures that multilayer thin film electrodes tend to experience. In order to increase the thermal conductivity from the working layer through to the back of the electrode, any _SiO2 layer present is advantageously kept as thin as possible. If a _SiO2 layer is used in contact with the first metal layer, then the underlying electrode substrate preferably has a strong bond to the _SiO2 , has good electrical insulating properties, has sufficient mechanical strength to support the attached film layer, and has High thermal conductivity (under typical electrode operating conditions and temperatures). Examples of suitable substrate materials meeting these criteria include, for example, pure Si; crystalline _SiO2 (quartz); amorphous _SiO2 (quartz), amorphous diamond-like carbon, or other types of doped glass or optical fibers, or Ceramic materials containing significant amounts of Si or N, such as Al ₆ Si ₂ O ₁₃ , Si ₃ N ₄ , or BN.

As disclosed above, the electrode structure of the present invention comprises a multilayer thin film working electrode preferably formed from two or more distinct metal layers. Many configurations or patterns are contemplated for these working electrodes. These include repeating sequences of different metal layers. These sequences may, for example, consist of 2-10 or more different film layers. In preferred embodiments, these working electrodes are deposited on substrates as disclosed above (e.g. silicon-based substrates coated with _SiO2 /TaN/α-Ta/Cu or coated with Cu substitutes as described above ) on the base layer or adhesive layer.

Assume M1, M2, M3, M4, M5, M6, M7, M8, M9, and M10 are possible metals for the working electrode. The following instructions can be 10 different examples of repeating sequences for the working electrode (where S = substrate, and B1 = optional barrier layer):

Simple paired repeats (M1/M2)

S/SiO2/TaN/α-Ta/(Cu or alternative)/M1/M2/M1/M2/...M1/M2/B1

1: S/SiO2/TaN/α-Ta/Cu/Zr/Ni/Zr/Ni/....../Zr/Ni/B1

2: S/SiO2/TaN/α-Ta/Ni/Nb/Ni/Nb/Ni/.../Nb/Ni/B1

Triple Repeat (M1/M2/M3)

S/SiO2/TaN/α-Ta/(Cu or alternative)/M2/M3/M1/M2/M3/.../M1/M2/M3/B1

3: S/SiO2/TaN/α-Ta/Cu/γ-U/Ni/Ti/γ-U/Ni/Ti/....../γ-U/Ni/Ti/B1

4: S/SiO2/TaN/α-Ta/Fe/γ-U/Ni/Ti/γ-U/Ni/Ti/....../γ-U/Ni/Ti/B1

Quadruple repeat (M1/M2/M3/M4)

S/SiO2/TaN/α-Ta/(Cu or alternative)/M1/M2/M3/M4/M1/M2/M3/M4/....../M1/M2/M3/M4/B1

5: S/SiO2/TaN/α-Ta/Cu/Pd/Ni/Nb/Cu/Pd/Ni/Nb/Cu/.../Pd/Ni/Nb/Cu/B1

6: S/SiO2/TaN/α-Ta/W/Ti/Ni/γ-U/Cu/Ti/Ni/γ-U/Cu/....../Ti/Ni/γ-U/Cu /B1

Mixed Repeat #1 ((M1/M2/M4)+(M8/M9))

S/SiO2/TaN/α-Ta/Cu/M1/M2/M4/M8/M9/M1/M2/M4/M8/M9/.../M1/M2/M4/M8/M9/B1

7: S/SiO2/TaN/α-Ta/Cu/α-Ta/Nb/W/Fe/Co/α-Ta/Nb/W/Fe/Co/....../α-Ta/Nb /W/Fe/Co/B1

8: S/SiO2/TaN/α-Ta/W/β-Ti/Ni/Nb/Co/Fe/β-Ti/Ni/Nb/Co/Fe/...β-Ti/Ni/ Nb/Co/Fe/B1

Mixed repeat sequence #2 ((M1+M2)+(M6)+(M8+M9)), where [M6] is a conductive thin film alloy or compound with special chemical, electronic, and/or magnetic properties

S/SiO2/TaN/α-Ta/Cu/M1/M2/M6/M8/M9/M1/M2/M6/M8/M9/.../M1/M2/M6/M8/M9/B1

9: S/SiO2/TaN/α-Ta/Cu/Au/Al/[CePd3]/Al/Ir/Au/Al/[CePd3]/Al/Ir/.../Au/Al/[ CePd3]/Al/Ir/B1

where M6=CePd ₃ , is an example of a heavy electron compound

10: S/SiO2/TaN/α-Ta/Cu/Nb/Mo/[NiFe]/Mo/β-Ti/Nb/Mo/[NiFe]/Mo/β-

Ti/....Nb/Mo/[NiFe]/Mo/β-Ti/B1

where M6 = NiFe, is an example of a ferromagnetic compound

11: S/SiO2/TaN/α-Ta/Cu/Au/Al/[ZrV2]/Al/Ir/Au/Al/[CePd3]/Al/Ir/.../Au/Al/[ CePd3]/Al/Ir/B1

where M6 = ZrV ₂ is an example of a compound that absorbs hydrogen up to ZrV ₂ H _5.2

Preferred electrode devices of the present invention also preferably include one or more barrier layers (eg, 14a-14c, Figure 1 ) overlying the electrode structure. For flat or curved planar electrodes, this may include top barrier layer 14a and side barrier layers 14b and 14c. When used, these barrier layers preferably have some or all of the following mechanical, electrical, and chemical properties:

1. Use as a diffusion barrier for hydrogen, deuterium, and/or protons and/or tritons.

2. Excellent thermal conductor.

3. High dielectric strength and low conductivity.

4. Low coefficient of thermal expansion (CTE).

5. Excellent adhesion to various metal and non-metal substrates.

6. Little or no reaction with aqueous electrolytes at expected operating temperatures.

7. Resistant to salt solution, acid, alkali, and other corrosive agents.

8. Thermal stability as high as possible, preferably up to 1,000 degrees Celsius.

9. High thermal shock resistance.

10. High stability under thermal cycling.

11. High elastic modulus, tensile strength, and compressive strength.

12. Low internal stress within a reasonable thickness range.

13. Relatively low deposition temperature (preferably well below 200 degrees Celsius).

14. Compatibility with various metal dopants.

In a preferred aspect of the invention there is provided a barrier layer made of an amorphous carbon coating, eg an amorphous diamond-like coating. Suitable such coating materials are commercially available under the trade name "Dylyn", manufactured and sold by Bekaert Advanced Coating Technologies, Amherst, New York, USA. Dylyn meets all of the above criteria and has the following properties:

1. Undoped Dylyn is an amorphous, pure carbon material composed of nanoscale particles that act as an excellent barrier against the diffusion and passage of hydrogen, deuterium, and/or protons

2. Diamond and diamond-like materials such as Dylyn have some of the highest known thermal conductivity of any material - about 20 W/ ^cm2

3. Undoped Dylyn has a dielectric strength of 4.0 mV/cm and a resistivity of 10 ¹⁶ ohms/cm

4. The coefficient of thermal expansion is 0.8×10 ^-6 K ^-1 , quite low and similar to SiO ₂ (0.5×10 ^-6 K ^-1 )

5. With Si, SiO ₂ , alumina ceramics, Pt, Pd, Rh and many other materials that can form carbides (such as Ti, Zr, V, Nb, Ta, Cr, Mo, W, Fe, Co, Ni, Al), and certain other carbide-forming rare earth metals have excellent adhesion and adhesion. Certain noble metals such as Ag, Au, and Cu do not bond well to Dylyn.

6. Stable up to 400 degrees Celsius in the presence of oxygen; greater than 1200 degrees Celsius in the absence of oxygen

7. Very low chemical reactivity and inert to almost all chemicals: the coating can withstand acids (hydrochloric acid or sulfuric acid; some formulations can even withstand HF), alkalis, dilute or concentrated salt solutions, and various other corrosives

8. See item 6 above.

9. High thermal shock resistance: hot Dylyn-coated samples can be dropped into liquid nitrogen without damage

10. Known from existing commercial applications to be very stable under deep thermal cycling

11. High elastic modulus of 100-400GPa, standard high tensile strength of 3.5×10 ⁹ Pascals, and high compressive strength of 10 ¹¹ Pascals.

12. In current commercial applications, 2 to 3 micron thick Dylyn coatings are typically deposited and have a relatively low internal stress of 100 to 1,000 MPa. Internal stress does increase with increasing Dylyn coating thickness: in this regard, the maximum thickness that can be deposited at a reasonable level of internal stress on an experimental basis is about 20 microns.

13. Depending on the material on which Dylyn is to be deposited, the deposition temperature of Dylyn is relatively low, ranging from a minimum of 25 degrees Celsius to a maximum of about 200 degrees Celsius. This feature is very attractive for the fabrication of the electrodes of the present invention, since the low deposition temperature of Dylyn does not affect the performance of the earlier fabrication steps involving the deposition and heat treatment (annealing) of the electrode's less adherent coating and working layers below the barrier layer. result.

14. In special cases where special properties are required, Au and Cu can be used in combination with Dylyn as a dopant. Pd, Pt, Rh and all of the previously listed preferred metals capable of forming carbides can also be used with Dylyn as a dopant in concentrations up to 40 atomic percent.

If Dylyn is used as the upper and side barrier (where one end of the electrode has an "open" exposed edge or surface of the working layer where electrons and hydrogen/deuterium can enter the electrode, as taught by Miley in WO0163010), then The preferred thickness of these barrier layers is 2 to 3 microns. If Dylyn is used as an upper barrier, it is preferably deposited on carbide-forming metals or other materials (such as Pt, Pd, Rh) and many other carbide-forming metals (such as Ti, Zr, V, Nb, Ta , Cr, Mo, W, Fe, Co, Ni, Al), and some other rare earth metals that can form carbides. If Dylyn is used as a side barrier (14b and 14c in Fig. 1), then the particular metal present in the working electrode and the adhesive coating is less important, since Dylyn's amorphous structure and enormous mechanical strength should make it Temporary layers of metals (such as certain noble metals like Ag, Au, Cu) that can "jump over" to Dylan only poorly.

In addition to its use as a barrier layer, amorphous carbon layers such as Dylyn can be used within electrode structures. For example, an amorphous carbon layer can be used between the substrate and the _SiO2 layer. Thus, an amorphous carbon layer, preferably about 2 to about 20 microns thick, can be used as a heat transfer buffer layer for transferring heat from an overlying layer to a substrate which can include an alumina ceramic, used as a substrate made of certain compatible metals. (such as extruded Al) and used as a compatible physical material for further heat transfer directly to the hot side of the thermoelectric and thermionic device operation. Such an amorphous carbon layer included in the thin film multilayer structure has the effect of surrounding the adherent coating or base layer and a large percentage of the working layers of the thin film multilayer electrode with the amorphous carbon coating. This helps to facilitate heat transfer from the working electrode layer and contributes to the overall stability of the entire multilayer structure, since Dylyn (or similar amorphous carbon coatings) has an advantageous combination of properties including: Deuterium/proton barrier capabilities, high dielectric strength, extreme thermal conductivity, and exceptional mechanical strength.

Another aspect of the invention includes the use of a graphite layer as a heat transfer buffer layer within the thin film electrode of the invention. Graphites suitable for use herein are described, for example, in U.S. Patent No. 6,037,032 (assigned to Oak Ridge National Laboratories). It is produced and marketed commercially under the trade name "PocoFoam Graphite" by PocoGraphite, Inc. (Decatur, Texas, U.S.A.).

PocoFoam is a specially prepared form of amorphous carbon that has excellent thermal conductivity and heat transfer capabilities relative to its weight. PocoFoam has a "foamed" honeycomb structure composed of mostly empty interconnected spherical voids, where the structure has a unique, highly graphitized arrangement of ligaments within the cell walls of the foam. Due to its porosity (typically 73% to 82%), PocoFoam does not offer preferred properties for use as a diffusion barrier for hydrogen, deuterium, and/or protons. However, PocoFoam graphitic carbon foam material can be advantageously used as an optional heat transfer buffer layer within the substrate layer of the thin film electrode of the present invention.

PocoFoam graphitic carbon has the following properties:

1. Thermal conductivity = 100 to 150+W/mK; 58-87 BTU.ft/ft ² .hr.°F. Heat transfer efficiency has been shown to be substantially better than aluminum or copper.

2. Resistivity = 300 to 1,000 micro-ohm inches.

3. Coefficient of thermal expansion ("CTE") = 2 to 3 μm/m°K; 1.1 to 1.6 μin/in-°F

4. Heat capacity = 0.7J/g-K; 0.17BTU/lb.°F

5. Compressive strength = 2.07MPa (density 0.5gm/cc); 300psi (density 31lb/ft ³ )

6. Average pore diameter = 350 microns; 0.0138 inches

7. Specific surface area => 4m ² /g; 19,500ft ² /lb

8. Open porosity = 96%; total porosity = 73-82%

The use of PocoFoam or other similar graphitic substances in electrodes of the invention may involve the use of a thin PocoFoam layer bonded directly to the substrate (ie used as layer 12a in Figure 1). All layers present above layer 12a may be present in the manner otherwise described herein, including the use of other layers in the adhesive coating, such as a tantalum nitride layer bonded to a graphite layer, a tantalum nitride layer bonded to a A tantalum (especially alpha-tantalum) layer on the tantalum layer, a copper or copper substitute layer bonded to the tantalum nitride layer, and a working electrode layer bonded to the copper or copper substitute layer, and the like. It should be noted in this regard that the use of PocoFoam or other graphitic materials as layer 12a may provide an alternative to silicon dioxide for use as layer 12a in embodiments of the present invention. The use of this graphite material can provide one or more of the following advantages:

1. Brings high thermal conductivity and efficient transfer of thermal energy through the bottom "base" layer of the electrode.

2. Provide sufficient adhesion and thermal stability for thin film layers of hcp/bcc TaN compounds deposited on top of graphite flakes or other layers.

3. The overall mass of the electrode structure can be reduced relative to the overall thermal conductivity and heat transfer capability of the device.

4. Having a relatively low electrical conductivity in the substrate layer compared to that of the metallic "working layer" of the electrode helps maximize the current density flowing through the working layer for a given electrical input power.

5. If TaN is deposited with a sufficient thickness to sufficiently fill the exposed voids in the uppermost flaky surface of the graphite foam immediately adjacent to the TaN layer, this can result in a substantially "depressed" concave upper surface for the entire TaN layer so that α-Ta is subsequently deposited. This technique produces a substantially concave substrate interface upon which the "upper" working thin film layer of the electrode can subsequently be deposited. The "dimples" in the TaN surface are reproduced with some attenuation in subsequent thin film layers deposited on top of the TaN. Thus, the use of porous graphite as an underlying layer enables the creation of an electrode interface with a concave curvature through its high percentage surface area.

6. Graphite flakes can be firmly adhered to the substrate. One suitable bonding and joining technique (trade name "S-bond") has been developed by Materials Research International (MRI) located in Lansdale, PA, U.S.A. . MRI's S-bond alloys 220 and 400 can bond PocoFoam to substrates at temperatures as low as 250-270 degrees Celsius and 410-420 degrees Celsius, respectively. These alloys wet and adhere to both surfaces, have low capillarity, and do not fill the pores in PocoFoam.

The invention also provides batteries incorporating electrodes of the invention. These may, for example, be dry or wet cells. For example, the electrode of the present invention can be introduced into an electrochemical cell as a cathode element, such as by Miley in an article entitled "FLAKE-RESISTANT MULTILAYER THIN-FILM ELECTRODES ANDELECTROLYTIC CELLS INCORPORATING SAME" , WO9807898 (published on February 26, 1998, which is hereby incorporated by reference in its entirety) as described in the application. Typically, these cells may comprise a packed bed of cathode electrode particles arranged in a flowing electrolyte cell. The packed particle bed allows for a flow area, and the packing fraction can be quite large, resulting in a large electrode surface area, which is ideal for providing high reaction rates per unit volume. Additionally, the packed pellet bed provides low pressure drop at moderate flow rates in the mode.

The electrodes of the present invention can also be described in WO0163010 (published on August 30, 2001) by Miley entitled "Battery, Components and Methods" (ELECTRICAL CELLS, COMPONENTS AND METHODS), which is hereby incorporated by reference in its entirety, and/or incorporated herein. The arrangement described in the disclosed battery device). Accordingly, an electrode according to the invention may be included in an electrode device having a substrate and an anode and a cathode provided at separate locations on the substrate and thus having a gap therebetween. In these arrangements, the multilayer thin-film electrode according to the invention is preferably provided as cathode. Operation of such an electrode device in the presence of an electrolyte (such as an aqueous electrolyte, optionally including heavy water) that fills the gap and contacts the electrode surfaces results in the electromigration of ions (such as protons or tritons) within the cathode and the generation of enrichment of these ions in the cathode Area.

The electrodes of the invention may also be included in solid state battery arrangements as described in above cited WO0163010, the latter comprising anodic and cathodic connections to counter electrodes provided as conductive elements. A solid state ion source is provided and arranged to deliver these ions into the conductive element. For example, such a solid state source may include a metal hydride or the corresponding deuteride for releasing hydrogen or deuterium in gaseous form, and a catalyst for decomposing gaseous hydrogen or deuterium to provide protons or tritons. Catalyst can be deposited onto the conductive element, and metal hydride can be deposited onto the catalyst. In this way, the gas released by the metal hydride (e.g. by heating) immediately contacts the catalyst to provide protons or tritons which, when a voltage drop is applied across the electrode, can then migrate to the working layer of the electrode (conductive element) of the invention and along its migration. A preferred arrangement includes a barrier layer as described above along at least a portion of the conductive element resistant to permeation by protons or tritons. The battery arrangement of this embodiment can advantageously be incorporated into devices of various geometries, such as cylindrical battery devices, such as described in Figures 5-8 of WO0163010.

In battery applications involving the recovery and/or conversion of heat, batteries incorporating electrodes of the invention may also include one or more thermoelectric converter elements thermally coupled to the thin film of the working electrode (see, shown in dashed lines in FIG. 1 The thermoelectric element 15). For example, the thermoelectric element and electrodes may be bonded to each other in a back-to-back manner or otherwise thermally coupled in a manner that facilitates heat transfer from the electrode device to the thermoelectric element.

For example, in one embodiment, a thermoelectric element may be used as a substrate for an electrode of the present invention comprising, as described above, a substrate with an anode and a cathode in separate positions thereon. As a mode of utilization, a plurality of such combined structures can be arranged in a battery in which the remaining space of the battery is reserved for electrolyte flow and space for coolant to flow through the battery (see WO0163010, Figure 4). Space for electrolyte flow occurs on the electrode side of the combined electrode/thermoelectric structure, providing electrolyte for operating the device. Space for coolant occurs on the thermoelectric element side of the combined structure. In this way, when the battery is operating, a temperature differential can be created across the thermoelectric converter element, which facilitates the generation of electrical energy.

The battery device of the present invention can be used, for example, for the electrolysis of electrolytes (such as water, forming hydrogen and oxygen gases), and can also be used in energy conversion devices or include batteries that generate heat and convert heat into electrical energy as needed, and/or for causing transmutation reaction. The apparatus of the present invention may also be used to provide densified regions of ions or hydrogen or isotopes thereof, increasing the possibility and facilitating further study of ion-ion reactions or ion-metal reactions, including studies of melting and related reactions. In this regard, these densified regions or local concentrations of hydrogen or its isotopes (including deuterium) may be induced by any suitable means including, for example, electromigration involving an applied current or other similar means, physical pressure diffusion gradients, electrolysis or other Electrolyte treatment, or any other means capable of obtaining local ion concentrations.

Although the present invention has been described in detail with reference to specific embodiments, it will be appreciated that modifications and changes in the disclosed embodiments may be made by those skilled in the art without departing from the spirit and scope of the invention. All such modifications and variations are intended to be covered by this invention. In addition, all publications cited herein represent the state of the art and are hereby incorporated by reference in their entirety as if each individual publication were individually and fully set forth by reference.

Claims (162)

1. An electrode for a battery, comprising: a) non-conductive substrate; b) an adhesive coating bonded to the non-conductive substrate; and c) a multilayer working electrode bonded to said adhesive coating, said multilayer working electrode comprising at least one layer of a first conductive metal, and at least one layer of a second conductive metal. 2. The electrode of claim 1, wherein: said non-conductive substrate has a silicon-containing surface. 3. The electrode of claim 1, wherein: said adhesive coating has multiple layers. 4. The electrode of claim 3, wherein: said adherent coating comprises a tantalum nitride layer bonded to said substrate. 5. The electrode of claim 4, wherein: said adherent coating comprises an alpha-tantalum layer bonded to said tantalum nitride layer. 6. The electrode of claim 5, wherein said adherent coating comprises a copper layer bonded to said alpha-tantalum layer. 7. The electrode of claim 1, wherein said substrate has a substantially planar surface, and wherein said adhesive coating and multilayer working electrode are bonded to said substantially planar surface. 8. The electrode of claim 1, wherein said substrate has a concave surface, and wherein said adhesive coating and multilayer working electrode are bonded onto said concave surface. 9. The electrode of claim 1, wherein said substrate has a convex surface, and wherein said adhesive coating and multilayer working electrode are bonded onto said convex surface. 10. The electrode of claim 1, wherein the first conductive metal and the second conductive metal have a Fermi energy difference of at least about 0.5. 11. The electrode of claim 1, wherein the at least one layer of the first conductive metal and the at least one layer of the second conductive metal have a thickness of less than about 10,000 Angstroms. 12. The electrode of claim 1, wherein the multilayer working electrode comprises at least four layers. 13. The electrode of claim 1, further comprising a barrier layer over said multilayer working electrode. 14. The electrode of claim 13, wherein said barrier layer comprises amorphous carbon. 15. An electrode for a battery comprising: a) Substrate; b) embrittlement-sensitive materials on said substrate; and c) A protective layer comprising oxygen-free copper to protect said embrittlement sensitive material. 16. The electrode of claim 15, wherein said substrate is non-conductive. 17. The electrode of claim 15, wherein said embrittlement sensitive material comprises tantalum or a tantalum compound. 18. The electrode of claim 17, wherein said embrittlement sensitive material comprises a tantalum nitride compound. 19. The electrode of claim 15, further comprising a multilayer working electrode adhered to said oxygen-free copper layer. 20. An electrode comprising: a) an electrode structure comprising a plurality of thin metal layers; and b) Amorphous carbon layer. 21. The electrode of claim 20, wherein said amorphous carbon layer is an amorphous diamond layer. 22. The electrode of claim 20, further comprising a non-conductive substrate to which the electrode structure is adhered. 23. The electrode of claim 22, further comprising an adhesive coating intermediate said electrode structure and said non-conductive substrate. 24. The electrode of claim 23, wherein the adhesive coating has multiple layers. 25. The electrode of claim 24, wherein said adherent coating comprises a layer of tantalum nitride adhered directly to said non-conductive substrate. 26. The electrode of claim 25, wherein said adherent coating further comprises an alpha-tantalum layer directly adhered to said tantalum nitride layer. 27. The electrode of claim 26, further comprising a copper layer bonded to said alpha-tantalum layer. 28. An electrode for an electrochemical cell comprising: a) an electrode structure comprising a plurality of thin metal layers; and b) wherein at least one of said thin metal layers has a bamboo grain pattern. 29. The electrode of claim 28, further comprising a non-conductive substrate, said electrode structure being adhered to said non-conductive substrate. 30. The electrode of claim 29, further comprising an adhesive coating intermediate said electrode structure and said non-conductive substrate. 31. The electrode of claim 30, wherein said adhesive coating has multiple layers. 32. The electrode of claim 31, wherein said adherent coating comprises a layer of tantalum nitride adhered directly to said non-conductive substrate. 33. The electrode of claim 32, wherein said adherent coating further comprises an alpha-tantalum layer directly adhered to said tantalum nitride layer. 34. The electrode of claim 33, further comprising a copper layer bonded to said alpha-tantalum layer. 35. An electrode for a battery comprising: a) an electrode structure comprising a plurality of thin metal layers; and b) wherein said thin metal layer comprises a first metal layer and a second metal layer; and c) wherein said first metal layer has a lattice mismatch of less than about 21% relative to said second metal layer. 36. The electrode of claim 35, wherein said first metal layer comprises alpha-tantalum. 37. The electrode of claim 36, wherein said second metal layer comprises a metal having a lattice constant mismatch of less than about 11 percent relative to said tantalum. 38. The electrode of claim 37, wherein said second metal layer comprises niobium. 39. The electrode of claim 37, wherein said second metal layer comprises beta-titanium. 40. The electrode of claim 37, wherein said second metal layer comprises tungsten. 41. The electrode of claim 37, wherein said second metal layer comprises molybdenum. 42. The electrode of claim 37, wherein said second metal layer comprises vanadium. 43. The electrode of claim 37, wherein said second metal layer comprises hafnium, erbium, dysprosium, samarium, gadolinium, or neodymium. 44. The electrode of claim 37, wherein said second metal layer comprises zirconium. 45. The electrode of claim 37, wherein said second metal layer comprises nickel. 46. The electrode of claim 36, wherein said second metal layer comprises a metal having a lattice constant mismatch relative to said tantalum of about 11% to about 21%. 47. The electrode of claim 46, wherein said second metal layer comprises iron. 48. The electrode of claim 46, wherein said second metal layer comprises cobalt. 49. The electrode of claim 46, wherein said second metal layer comprises rhodium. 50. The electrode of claim 46, wherein said second metal layer comprises iridium. 51. The electrode of claim 46, wherein said second metal layer comprises rhenium. 52. The electrode of claim 46, wherein said second metal layer comprises osmium. 53. The electrode of claim 46, wherein said second metal layer comprises palladium. 54. The electrode of claim 46, wherein said second metal layer comprises ruthenium. 55. The electrode of claim 46, wherein said second metal layer comprises platinum. 56. The electrode of claim 37, wherein said second metal layer comprises chromium. 57. The electrode of claim 35, wherein at least one of the first metal layer and the second metal layer comprises a metal alloy. 58. The electrode of claim 35, wherein at least one of said first and second metal layers has been formed by sputter deposition. 59. The electrode of claim 35, wherein at least one of the first metal layer and the second metal layer has been formed by chemical vapor deposition. 60. The electrode of claim 35, wherein at least one of said first and second metal layers has been formed by epitaxial deposition. 61. The electrode of claim 35, wherein at least one of said first and second metal layers has been formed by electrodeposition. 62. The electrode of claim 35, wherein at least one of said first and second metal layers has been formed by electroless deposition. 63. The electrode of claim 62, wherein at least one of said first and second metal layers comprises a metal selected from the group consisting of copper, gold, nickel, palladium, rhodium, silver, cobalt, and iron. 64. The electrode of claim 35, wherein at least one of said first and second metal layers has been formed by displacement plating deposition. 65. The electrode of claim 64, wherein at least one of said first and second metal layers comprises a metal selected from the group consisting of silver, gold, platinum, palladium, rhodium, iridium, rhenium, osmium, and ruthenium. 66. The electrode of claim 35, wherein at least one of the first metal layer and the second metal layer has been annealed. 67. The electrode of claim 57, wherein said metal alloy layer has been formed by physical vapor deposition magnetron sputtering. 68. The electrode of claim 35, wherein at least one of the first metal layer and the second metal layer has been formed by heteroepitaxial multilayer growth. 69. The electrode of claim 35, wherein at least one of said first and second metal layers has been formed using an atomic surfactant. 70. An electrode for a battery comprising: Substrate; a tantalum nitride layer adhered to the substrate; a tantalum layer adhered to the tantalum nitride layer; a copper layer bonded to the tantalum layer; and Bonded to the first metal layer on the copper layer. 71. The electrode of claim 70, wherein said first metal layer comprises neodymium. 72. The electrode of claim 71, further comprising a second metal layer bonded to said first metal layer. 73. The electrode of claim 72, wherein said second metal layer comprises a metal selected from the group consisting of copper, iridium, niobium, nickel, palladium, platinum, rhodium, tantalum, titanium, uranium, zirconium, silver, gold, molybdenum, vanadium, and tungsten. Element. 74. The electrode of claim 73, wherein said composition is selected from the group consisting of copper, iridium, niobium, nickel, palladium, platinum, rhodium, tantalum, titanium, uranium and zirconium. 75. The electrode of claim 70, wherein said first metal layer comprises nickel. 76. The electrode of claim 75, further comprising a second metal layer bonded to said first metal layer. 77. The electrode of claim 76, wherein said second metal layer comprises a metal selected from the group consisting of copper, iridium, niobium, neodymium, palladium, rhodium, tantalum, titanium, uranium, zirconium, silver, gold, molybdenum, platinum, vanadium, and tungsten. Element. 78. The electrode of claim 77, wherein said composition is selected from the group consisting of copper, iridium, niobium, neodymium, palladium, rhodium, tantalum, titanium, uranium, and zirconium. 79. The electrode of claim 70, wherein said first metal layer comprises samarium. 80. The electrode of claim 79, further comprising a second metal layer bonded to said first metal layer. 81. The electrode of claim 80, wherein said second metal layer comprises a metal selected from the group consisting of copper, dysprosium, erbium, gadolinium, niobium, neodymium, nickel, palladium, platinum, rhenium, ruthenium, beta-titanium, vanadium, tungsten, zirconium, Constituents of cobalt, chromium, iron, palladium, platinum, rhenium, and rhodium. 82. The electrode of claim 81, wherein said composition is selected from the group consisting of copper, dysprosium, erbium, gadolinium, niobium, neodymium, nickel, palladium, platinum, rhenium, ruthenium, beta-titanium, vanadium, tungsten, and zirconium. 83. The electrode of claim 70, wherein said first metal layer comprises uranium. 84. The electrode of claim 75, further comprising a second metal layer bonded to said first metal layer. 85. The electrode of claim 84, wherein said second metal layer comprises a composition selected from the group consisting of copper, magnesium, neodymium, nickel, rhodium, titanium, thallium, aluminum, gold, palladium, platinum, and vanadium. 86. The electrode of claim 85, wherein said composition is selected from the group consisting of copper, magnesium, neodymium, nickel, rhodium, titanium, and thallium. 87. The electrode of claim 70, wherein said first metal layer comprises thallium. 88. The electrode of claim 87, further comprising a second metal layer bonded to said first metal layer. 89. The electrode of claim 87, wherein said second metal layer comprises a composition selected from the group consisting of copper, magnesium, uranium and aluminum. 90. The electrode of claim 89, wherein said constituent is selected from the group consisting of copper, magnesium, and uranium. 91. The electrode of claim 70, wherein said first metal layer comprises rhodium. 92. The electrode of claim 91, further comprising a second metal layer bonded to said first metal layer. 93. The electrode of claim 92, wherein said second metal layer comprises a composition selected from the group consisting of silver, aluminum, copper, iridium, neodymium, nickel, palladium, platinum, uranium, zirconium, molybdenum, niobium, tantalum, titanium, and tungsten . 94. The electrode of claim 93, wherein said composition is selected from the group consisting of silver, aluminum, copper, iridium, neodymium, nickel, palladium, platinum, uranium, and zirconium. 95. The electrode of claim 70, wherein said first metal layer comprises iridium. 96. The electrode of claim 95, further comprising a second metal layer bonded to said first metal layer. 97. The electrode of claim 96, wherein said second metal layer comprises a material selected from the group consisting of silver, gold, copper, neodymium, nickel, palladium, platinum, rhodium, zirconium, molybdenum, niobium, tantalum, and titanium. 98. The electrode of claim 97, wherein said composition is selected from the group consisting of silver, gold, copper, neodymium, nickel, palladium, platinum, rhodium, and zirconium. 99. The electrode of claim 70, wherein said first metal layer comprises palladium. 100. The electrode of claim 99, further comprising a second metal layer bonded to said first metal layer. 101. The electrode of claim 100, wherein said second metal layer comprises a composition selected from the group consisting of silver, gold, copper, iridium, neodymium, nickel, platinum, rhodium, molybdenum, niobium, tantalum, titanium, uranium, and zirconium. 102. The electrode of claim 101, wherein said composition is selected from the group consisting of silver, gold, copper, iridium, neodymium, nickel, platinum, and rhodium. 103. The electrode of claim 70, wherein said first metal layer comprises titanium. 104. The electrode of claim 103, further comprising a second metal layer bonded to said first metal layer. 105. The electrode of claim 104, wherein said second metal layer comprises a metal selected from the group consisting of copper, molybdenum, niobium, neodymium, nickel, tantalum, uranium, vanadium, tungsten, zirconium, cobalt, iron, iridium, palladium, platinum, rhenium, and rhodium components. 106. The electrode of claim 105, wherein said composition is selected from the group consisting of copper, molybdenum, niobium, neodymium, nickel, tantalum, uranium, vanadium, tungsten, and zirconium. 107. The electrode of claim 70, wherein said first metal layer comprises platinum. 108. The electrode of claim 107, further comprising a second metal layer bonded to said first metal layer. 109. The electrode of claim 108, wherein said second metal layer comprises a composition selected from the group consisting of gold, copper, iridium, neodymium, palladium, rhodium, molybdenum, niobium, nickel, tantalum, titanium, uranium, and zirconium. 110. The electrode of claim 109, wherein said composition is selected from the group consisting of gold, copper, iridium, neodymium, palladium, and rhodium. 111. The electrode of claim 70, wherein said first metal layer comprises niobium. 112. The electrode of claim 111, further comprising a second metal layer bonded to said first metal layer. 113. The electrode of claim 112, wherein said second metal layer comprises a metal selected from the group consisting of copper, molybdenum, neodymium, nickel, tantalum, titanium, vanadium, tungsten, zirconium, cobalt, iron, iridium, osmium, palladium, platinum, rhenium, Rhodium, and ruthenium components. 114. The electrode of claim 113, wherein said composition is selected from the group consisting of copper, molybdenum, neodymium, nickel, tantalum, titanium, vanadium, tungsten, and zirconium. 115. The electrode of claim 70, wherein said first metal layer comprises aluminum. 116. The electrode of claim 115, further comprising a second metal layer bonded to said first metal layer. 117. The electrode of claim 116, wherein said second metal layer comprises a member selected from the group consisting of gold, copper, thallium, uranium, and zirconium. 118. The electrode of claim 117, wherein said component is gold. 119. The electrode of claim 70, wherein said first metal layer comprises magnesium. 120. The electrode of claim 119, further comprising a second metal layer bonded to said first metal layer. 121. The electrode of claim 120, wherein said second metal layer comprises a member selected from the group consisting of thallium, uranium and copper. 122. The electrode of claim 121, wherein said constituent is selected from the group consisting of thallium and uranium. 123. The electrode of claim 70, wherein said first metal layer comprises gold. 124. The electrode of claim 123, further comprising a second metal layer bonded to said first metal layer. 125. The electrode of claim 124, wherein said second metal layer comprises a member selected from the group consisting of silver, aluminum, iridium, palladium, platinum, rhodium, copper, neodymium, nickel, thorium, uranium, and zirconium. 126. The electrode of claim 125, wherein said composition is selected from the group consisting of silver, aluminum, iridium, palladium, platinum, and rhodium. 127. The electrode of claim 70, wherein said first metal layer comprises molybdenum. 128. The electrode of claim 127, further comprising a second metal layer bonded to said first metal layer. 129. The electrode of claim 128, wherein said second metal layer comprises a metal selected from the group consisting of iron, niobium, tantalum, titanium, vanadium, tungsten, zirconium, cobalt, iridium, neodymium, nickel, osmium, palladium, platinum, rhenium, rhodium, and ruthenium components. 130. The electrode of claim 129, wherein said composition is selected from the group consisting of iron, niobium, tantalum, titanium, vanadium, tungsten, and zirconium. 131. The electrode of claim 70, wherein said first metal layer comprises silver. 132. The electrode of claim 131, further comprising a second metal layer bonded to said first metal layer. 133. The electrode of claim 132, wherein said second metal layer comprises a composition selected from the group consisting of aluminum, gold, iridium, palladium, rhodium, copper, neodymium, nickel, thallium, uranium, and zirconium. 134. The electrode of claim 133, wherein said composition is selected from the group consisting of aluminum, gold, iridium, palladium, and rhodium. 135. The electrode of claim 70, wherein said first metal layer comprises vanadium. 136. The electrode of claim 135, further comprising a second metal layer bonded to said first metal layer. 137. The electrode of claim 136, wherein said second metal layer comprises a composition selected from the group consisting of cobalt, iron, molybdenum, niobium, osmium, rhenium, tantalum, titanium, tungsten, copper, neodymium, nickel, ruthenium, uranium, and zirconium . 138. The electrode of claim 137, wherein said composition is selected from the group consisting of cobalt, iron, molybdenum, niobium, osmium, rhenium, tantalum, titanium, and tungsten. 139. The electrode of claim 70, wherein said first metal layer comprises iron. 140. The electrode of claim 139, further comprising a second metal layer bonded to said first metal layer. 141. The electrode of claim 140, wherein said second metal layer comprises a composition selected from the group consisting of cobalt, molybdenum, osmium, rhenium, ruthenium, vanadium, tungsten, niobium, tantalum, and titanium. 142. The electrode of claim 141, wherein said constituent is selected from the group consisting of cobalt, molybdenum, osmium, rhenium, ruthenium, vanadium, and tungsten. 143. The electrode of claim 70, wherein said first metal layer comprises gadolinium. 144. The electrode of claim 143, further comprising a second metal layer bonded to said first metal layer. 145. The electrode of claim 144, wherein said second metal layer comprises a compound selected from the group consisting of copper, dysprosium, erbium, iridium, niobium, neodymium, nickel, palladium, platinum, rhodium, samarium, alpha-tantalum, beta-titanium, gamma- Composition of uranium, zirconium, silver, gold, hafnium, molybdenum, vanadium, and tungsten. 146. The electrode of claim 145, wherein said composition is selected from the group consisting of copper, dysprosium, erbium, iridium, niobium, neodymium, nickel, palladium, platinum, rhodium, samarium, alpha-tantalum, beta-titanium, gamma-uranium, and zirconium . 147. The electrode of claim 70, wherein said first metal layer comprises dysprosium. 148. The electrode of claim 147, further comprising a second metal layer bonded to said first metal layer. 149. The electrode of claim 148, wherein said second metal layer comprises copper, erbium, gadolinium, iridium, niobium, neodymium, nickel, palladium, platinum, rhodium, samarium, alpha-tantalum, beta-titanium, gamma- Composition of uranium, zirconium, silver, gold, hafnium, molybdenum, vanadium, and tungsten. 150. The electrode of claim 149, wherein said composition is selected from the group consisting of copper, erbium, gadolinium, iridium, niobium, neodymium, nickel, palladium, platinum, rhodium, samarium, alpha-tantalum, beta-titanium, gamma-uranium, and zirconium . 151. The electrode of claim 70, wherein said first metal layer comprises hafnium. 152. The electrode of claim 151, further comprising a second metal layer bonded to said first metal layer. 153. The electrode of claim 152, wherein said second metal layer comprises a compound selected from the group consisting of chromium, molybdenum, niobium, nickel, alpha-tantalum, beta-titanium, vanadium, tungsten, zirconium, cobalt, dysprosium, erbium, iron, iridium, Composition of gadolinium, neodymium, osmium, rhenium, rhodium, ruthenium, and samarium. 154. The electrode of claim 153, wherein said composition is selected from the group consisting of chromium, molybdenum, niobium, nickel, alpha-tantalum, beta-titanium, vanadium, tungsten, zirconium. 155. An electrode for a battery comprising: a) Substrate; b) a multilayer working electrode on said substrate, said multilayer working electrode comprising at least one layer of a first conductive metal, and at least one layer of a second conductive metal; and wherein the first conductive metal and the second conductive metal have a lattice constant mismatch of less than about 21% when saturated with hydrogen or an isotope thereof. 156. The electrode of claim 155, wherein said first conductive metal and said second conductive metal have substantially equivalent swelling when saturated with hydrogen or an isotope thereof. 157. The electrode of claim 155, wherein the first conductive metal and the second conductive metal have a reduced lattice constant mismatch when saturated with hydrogen and its isotopes. 158. An electrode for a battery which, in use, exhibits resistance to electromigration damage, comprising: a) Substrate; b) a multilayer working electrode on said substrate, said multilayer working electrode comprising at least one layer of a first conductive metal, and at least one layer of a second conductive metal; and wherein at least one of the first conductive metal and the second conductive metal has an average grain size diameter at least about equal to the thickness of the layer in which it is comprised. 159. A battery device comprising the electrodes of any of claims 1, 15, 20, 28, 35, 70, 155 and 158. 160. A method for localizing a concentration of ions of hydrogen or an isotope thereof comprising: providing the battery device of claim 159; and causing said ions to form a localized concentration of ions within said electrode by electromigration. 161. A method for localizing the concentration of ions of hydrogen or an isotope thereof, comprising: providing an article having a substrate and thereon a multilayer structure as defined in any of claims 1, 15, 20, 28, 35, 70, 155 and 158; and The concentration of ions of hydrogen or isotopes thereof is localized within the multilayer structure. 162. The method of claim 161, wherein said localization is caused at least in part by electromigration.

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